1. Field of the Invention
The present general inventive concept relates to a developing cartridge to develop an electrostatic latent image on a photosensitive body and an electrophotographic image forming apparatus including the same.
2. Description of the Related Art
In general, electrophotographic image forming apparatuses form an electrostatic latent image corresponding to a desired image on a photosensitive body by radiating light onto the photosensitive body charged to a uniform potential, develop the electrostatic latent image using a toner to form a toner image, transfer the toner image onto a sheet of paper, and fuse the toner image on the sheet of paper, thereby forming the desired image.
The electrophotographic image forming apparatus includes a developing cartridge. The developing cartridge includes a developing roller facing the photosensitive body and an agitator to feed the toner to the developing roller.
Referring to FIGS. 1 and 2, a conventional agitator includes a body 1 and an agitating film 3. Bosses 2 are provided on one side of the body 1. Coupling holes 4 through which the bosses 2 perforate are provided in the agitating film 3. As illustrated in FIG. 2, the agitating film 3 is inserted into the body 1 such that the bosses 2 perforate through the coupling holes 4 and a heat is then applied to the bosses 2. To this end, portions of the bosses 2 are fused to form fusing portions 6 having a size greater than that of the coupling holes 4. Thus, the agitating film 3 is coupled to the body 1. When the conventional agitator rotates, the agitating film 3 contacts an inner wall 5 of a developing cartridge. One end 3a of the agitating film 3 contacting the inner wall 5 of the developing cartridge is curved toward the body 1, as illustrated in FIG. 2. However, a second end 3b of the agitating film 3 is curved in an opposite direction of the body 1, as illustrated in FIG. 2. Accordingly, the agitating film 3 may be split. In addition, when the heat is applied to the bosses 2, the agitating film 3 may be damaged by the heat.
FIG. 3 is a view illustrating a conventional agitator. Referring to FIGS. 2 and 3, a reinforcement member 7 made of a material harder than that of the agitating film 3 is attached to the agitating film 3, a heat is applied to the bosses 2, and the agitating film 3 and the reinforcement member 7 are fixed on the body 1. The rienforcement member 7 prevents the agitating film 3 from being damaged by the heat, and supports the other end 3b of the agitating film 3 such that the other end 3b is prevented from being curved when the conventional agitator rotates. However, since this conventional agitator further requires the reinforcement member 7, a cost of components increases. Also, since a process of assembling the reinforcement member 7 is further required, a production cost increases. Accordingly, prices of the developing cartridge and the image forming apparatus increase.
Recently, price competition of the electrophotographic image forming apparatus has been intensified. Further, when the toner contained in the developing cartridge is used up, the developing cartridge must be replaced. Thus, if the price of the developing cartridge increases, the price competitiveness is reduced.